Brake systems for vehicles rely on a vacuum brake booster connected to the vehicle's intake manifold. Conventionally positioned between the booster and the manifold is an aspirator that provides a narrow flow introduction gap from the air suction flow to the main flow (the motive flow) that functions at a low vacuum pressure all the way to negative 60 kPa.
Under some engine operation conditions (such as during engine idle), pressure inside the brake boost tank maybe higher than intake manifold. The narrow gap of the aspirator prevents a high flow rate from the boost tank to the intake manifold. Accordingly, a separate flow bypass is required to quickly flow air out of the brake boost tank to achieve desired performance.
The separate flow bypass required by known brake arrangements introduces an additional component that adds cost to the arrangement. In addition, the requirement for the separate flow bypass introduces another element into the vehicle braking system that is subject to failure.
Thus, known brake systems that include aspirators are subject to improvement. Accordingly, a brake system for use with a vehicle that provides an advantage over known systems remains wanting.